Average RMS and Power

Question 1

What is the Peak value of the voltage

Answer 1

The maximum possible positive or negative value

Question 2

What is the Peak to peak value of the voltage

Answer 2

Range between the minimum and maximum value

Question 3

What is meant by the Average or mean value

Answer 3

Value you obtain if you smoothed the wave form

Question 4

What is meant by the Root Mean Square value

Answer 4

Essentially a measure of the power in a resistive load

Question 5

What is the integral to calculate the average value

Answer 5

X=1/T* (integral between 0 and T of x(t)dt)

Question 6

What is the integral to calculate the RMS

Answer 6

X= 1/T*(integral between 0 and T of x(t)^2dt)

Question 7

For a pure AC wave what is the RMS value equivalent to

Answer 7

Standard Deviation

Question 8

What does the average value tell you bout steady current

Answer 8

How much steady current you need to pass through a component for the same amount of time as you pass a variable current, so that the same amount of charge gets transferred

Question 9

What is the average power equal to

Answer 9

Pave=1/T *(integral between 0 and T of v(t)I(t)dt

Question 10

What is the average power equal

Answer 10

Pave =Vdc*Idc

Question 11

What are the 2 equations for average power in a resistive load

Answer 11

Pave=RIrms^2

Pave=v^2rms/R

Question 12

At steady state current or Irms gives the same average power dissipation in a resistor as……???

Answer 12

The Varying current

Question 13

R.M.S value is tells you how effective the wave is at what?

Answer 13

Dissipating power in a resistor

Question 14

What is the equation for the RMS value of the current.

Answer 14

Irms= square root of (1/T*integral between 0 and T of I(t)^2 dt

Question 15

What is the equation for the Vrms for a sine wave

Answer 15

Vrms=Vpk/square root 2

Question 16

Is the equation for Vrms for a sine wave a general result

Answer 16

No, other waves have different RMS values

Question 17

Why is the Mains value stated as an RMS value and what is the RMS value and Peak value

Answer 17

Because the RMS value tells you about power being dissipated which is what is paid for
Vrms= 230V
Vpk= 325V

Question 18

What are the amplitude RMS values of Sin waves, Square Waves and Saw tooth functions

Answer 18

Sin waves= A/root 2
Square waves= A
Saw tooth waves= A/root 3

Question 19

What is the Vrms for a square wave with an amplitude +-Vo

Answer 19

Vo

Question 20

Full Wave rectification is the same as taking the…..

Answer 20

Absolute value (magnitude)

Question 21

What is the equation for a fully rectified sin wave

Answer 21

V(t)=Vpk|sinwt|

Question 22

What happens the frequency during rectification.

Answer 22

It is doubled

Question 23

For full wave Rectification what are the limits of integration

Answer 23

0 and T/2

Question 24

For a rectified sin wave what is the Vavg

Answer 24

Vavg=2/pi * vpk=0.64Vpk

Question 25

What is the Vrms for a rectified sin wave

Answer 25

Vrms=1/root2 *vpk=0.71 Vpk

Question 26

What must be true must be about Vrms and Vavg

Answer 26

Vrms is greater than or equal to Vavg

Question 27

What effect does full wave rectification have on the RMS value

Answer 27

No effect so the Vrms of a full rectified wave is Vpk/root 2

Question 28

What can be helpful when calculating averages

Answer 28

Symmetry

Question 29

What portion of the Period of the wave do you need to consider for a triangle wave

Answer 29

T/4

Question 30

For a square wave what is the Vr.m.s

Answer 30

Vr.m.s = Vpeak aka the amplitude of the square wave

Question 31

What is the equation relating Vavg and Duty cycle

Answer 31

Vavg = DVon + (1-D)Voff

Question 32

What is the equation relating Vr.m.s and duty cycle

Answer 32

Vr.m.s= square root of (DV^2on + (1-D)V^2off)

Question 33

For half wave rectification of a sin wave What is the integral for the Vavg

Answer 33

Vavg=(1/T) x intergrall of (Vosinwt) dt btween 0 and T/2

Question 34

For half wave rectification of a sin wave what is the Vr.m.s

Answer 34

Vr.m.s= Vo/2

Question 35

For full wave rectification of a sine wave what are the equations for Vavg and Vr.m.s

Answer 35

``` Vavg = 2Vo/pi Vr.m.s = Vo/(root 2) ```

Question 36

For a triangle wave how does the peak voltage relate to r.m.s voltage

Answer 36

Vpk = Vr.m.s x (root3)